Phoneutria is a genus of spiders which are all dangerous to human beings. Their venom is more powerful, drop for drop, than other venoms, and, since they are large spiders, they have much of it. They are called "armed spiders" in Portuguese because their venom is a powerful weapon. Their body length goes from 17 to 48 mm (0.7–1.9 in).[1]

These spiders live in Central America and South America. They hide in the daytime and walk around looking for food at night. So their English name is "Wandering Spider." There are several species, and only Phoneutria fera can kill healthy adult humans.[2] Fortunately, the Phoneutria spiders usually do not inject venom when they bite humans, or, if they do inject venom, they do not use much. Phoneutria fera spiders are found in the Amazon Rainforest, so they seldom encounter humans. People who get bitten by Phoneutria spiders can be given an antivenom, so those people who come out of the jungle with a bite will be treated and will not die, and those people who die in the jungle may not be reported to the government.